Bond issues to finance school construction in Fairfax and Prince William counties remained in doubt in early returns from yesterdays referendums, while bonds for parkland and acquisition and development in Fairfax and Loudoun counties were winning. A school bond issue was winning in Loundoun.

The Fairfax school bonds would finance construction of two elementary schools and renovation of 15 old ones at a cost of $19,730,000 and air-conditioning of the old schools at a cost of $4,145,000.

The park proposal, calling for $51 million in bond money to be spent largely on extensive community park development and acquisition of additional buffer space around Lake Occoquan, held a narrow lead in Fairfax.

With almost three-quarters of the Loudoun returns in, a proposal to spend $2 million to improve the county's Circuit Court facilities was losing heavily. Another proposal, to spend $300,000 to acquire more landfill in Loudoun, was losing by a narrow margin.

In Fairfax, both the school and park bond issues had broad support among civic and special-interest groups.But before the Board of Supervisors gave their unanimous endorsement to a referendum on the school bond proposals, some members expessed their annoyance at the school board's decision to seek a spring, rather than fall, vote.

Supervisor Alan H. Magazine (D-Mason) complained that the school board dumped the issue in the supervisors' laps with hardly any warning. But school board chairman Rodney J. Page replied that the spring vote target had been set as long ago as last fall.

Magazine's concern, shared by some other officials, was that voters would rebel against supporting two bond issues totaling more than $75 million.

Several times recently Fairfax voters had turned down school bonds. Furthermore, as the county's population has grown older, the schools' most loyal constituency - parents of young children - has been shrinking as a percentage of the total voters.

School officials also found themselves advocating more new construction at a time when the school-age population was declining. This was because school-age population was exploding in the rapidly developing western and southern areas of the county.

The park bond referendum encountered little of the caviling that was aimed at the school proposal. Some officials, like Supervisor Maris B. Travesky (R-Springfield), felt that park bond supporters were better organized.

In addition, the parks issue divide the benefits almost equally among the eight magisterial districts, the older and never areas alike.

The Prince William County school bond referendum had been trimmed back from $26.3 million defeated last spring by a vote of 4,606 to 3,046. Not on yesterday's nearly $15 million referendum were three elementary schools included on last year's referendum. Two of the schools are being built from proceeds of the sale of schools to the city of Manassas and plans for the construction of the third have been shelved, largely because the extension of year-round schooling has relieved overcrowding.

While most of the money in the bond issue was earmarked for a new high school in the Dumfries-Triangle area, $1.7 million was provided for renovation and modernization at 37 facilities throughout the country.